Nanostructures for process monitoring and feedback control

ABSTRACT

Various techniques are provided to utilize nanostructures for process monitoring and feedback control. In one example, a method includes forming a layer of material including nanostructures distributed therein. Each nanostructure includes a quantum dot and a shell encompassing the quantum dot. The shells and quantum dots are configured to emit a first and second wavelength, respectively, in response to an excitation signal. The method further includes applying the excitation signal to at least a portion of the layer of material. The method further includes detecting an emitted signal from the portion of the layer of material, where the emitted signal is provided by at least a subset of the nanostructures in response to the excitation signal. The method further includes determining whether a manufacturing characteristic has been satisfied based at least on a wavelength of the emitted signal. Related systems and products are also provided.

BACKGROUND Technical Field

The present application generally relates to the monitoring ofmanufacturing processes and, more specifically, to nanostructures forprocess monitoring and feedback control of additive manufacturingprocesses.

Related Art

Additive manufacturing (e.g., also referred to as three-dimensional (3D)printing), is a flexible and cost effective technology for makingcomplex products. In additive manufacturing, an object is formed bydepositing material in a layer-based approach. In this regard,successive layers of material are built up on top of each other untilthe final object is fully formed. Related manufacturing operations(e.g., the application of temperature, pressure, and/or otheroperations) may be performed before, during, or after various layers aredeposited.

Unfortunately, many conventional additive manufacturing processes lackefficient quality control measures. In many cases, a manufactured objectmay not be thoroughly inspected until the manufacturing process isalready complete. This can prove costly and inefficient since a mistakein manufacture may not be detected until it is too late to fix. Indeed,considerable time, energy, and material may be wasted if themanufactured object is rendered unusable by such a mistake.

Although certain non-destructive evaluation (NDE) measures may sometimesbe used to evaluate the quality of a manufacturing process (e.g.,inspection by X-ray computed tomography or ultrasound), such NDEapproaches tend to be very costly, time consuming, and/or inadequate foreffective evaluation. Therefore, there is a need for an improvedapproach for inspecting products formed by additive manufacturingprocesses.

SUMMARY

In accordance with various embodiments further discussed herein, quantumdot-based nanostructures are provided in an additive manufacturingmaterial. The nanostructures may be used to evaluate whether amanufacturing characteristic of an additive manufacturing process hasbeen satisfied. The nanostructures may include a quantum dot encompassedby a shell, wherein the quantum dot and the shell are configured to emitdifferent wavelengths in response to an excitation signal (e.g., alsoreferred to as a verification signal). The shell may be configured to beremoved when a corresponding manufacturing characteristic has beensatisfied. By exciting the nanostructures during an additivemanufacturing process (e.g., during or between the deposition ofdifferent layers), the manufacturing characteristic can be evaluatedwhile the manufacturing process is in progress. As a result, themanufacturing process may be interrupted if the manufacturingcharacteristic is not satisfied, thus saving significant time, cost, andmaterial.

According to an embodiment, a method may include forming a layer ofmaterial including a plurality of nanostructures distributed therein.Each nanostructure may include a quantum dot and a shell encompassingthe quantum dot. The shells may be configured to emit a first wavelengthin response to an excitation signal. The quantum dots may be configuredto emit a second wavelength in response to the excitation signal. Themethod may further include applying the excitation signal to at least aportion of the layer of material. The method may further includedetecting an emitted signal from the portion of the layer of material,where the emitted signal may be provided by at least a subset of theplurality of nanostructures in response to the excitation signal. Themethod may further include determining whether a manufacturingcharacteristic has been satisfied based at least on a wavelength of theemitted signal

According to another embodiment, a system may include a manufacturingdevice configured to form a layer of material including a plurality ofnanostructures distributed therein. Each nanostructure may include aquantum dot and a shell encompassing the quantum dot. The shells may beconfigured to emit a first wavelength in response to an excitationsignal. The quantum dots may be configured to emit a second wavelengthin response to the excitation signal. The system may further include anexcitation device configured to apply the excitation signal to at leasta portion of the layer of material. The system may further include adetection device configured to detect an emitted signal from the portionof the layer of material, where the emitted signal is provided by atleast a subset of the plurality of nanostructures in response to theexcitation signal. The system may further include a computing deviceconfigured to determine whether a manufacturing characteristic has beensatisfied based at least on a wavelength of the emitted signal.

According to another embodiment, a product may include an additivemanufacturing material. The product may further include a plurality ofnanostructures distributed within the material and configured to receivean excitation signal and provide an emitted signal in response thereto.Each nanostructure may include a quantum dot and a shell encompassingthe quantum dot. The shells may be configured to emit a first wavelengthin response to the excitation signal based on a first band gapassociated with the shells. The shells may be configured to be removedfrom the nanostructures in response to a manufacturing operationperformed on the product. The removal of the shells may cause theemitted signal to exhibit the second wavelength. The quantum dots may beconfigured to emit a second wavelength in response to the excitationsignal based on a second band gap associated with the quantum dots.

The scope of the invention is defined by the claims, which areincorporated into this section by reference. A more completeunderstanding of embodiments of the invention will be afforded to thoseskilled in the art, as well as a realization of additional advantagesthereof, by a consideration of the following detailed description of oneor more embodiments. Reference will be made to the appended sheets ofdrawings that will first be described briefly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a system for using nanostructures to monitor amanufacturing process in accordance with an embodiment of the presentdisclosure.

FIG. 2 illustrates a block diagram of a computing device for monitoringa manufacturing process in accordance with an embodiment of the presentdisclosure.

FIG. 3 illustrates nanostructures in layers of an object in accordancewith an embodiment of the present disclosure.

FIG. 4 illustrates forming of a layer of an object and evaluating thelayer in accordance with an embodiment of the present disclosure.

FIG. 5 illustrates different signals emitted by an object in response toan excitation signal in accordance with an embodiment of the presentdisclosure.

FIG. 6A illustrates an example of a nanostructure in accordance with anembodiment of the present disclosure.

FIG. 6B illustrates an example of the nanostructure of FIG. 6A with theshell partially removed in accordance with an embodiment of the presentdisclosure.

FIG. 6C illustrates an example of the nanostructure of FIG. 6A with theshell completely removed in accordance with an embodiment of the presentdisclosure.

FIG. 7 illustrates a flow diagram of an example process for usingnanostructures to monitor a manufacturing process in accordance with anembodiment of the present disclosure.

Embodiments of the present disclosure and their advantages are bestunderstood by referring to the detailed description that follows. Itshould be appreciated that like reference numerals are used to identifylike elements illustrated in one or more of the figures, whereinshowings therein are for purposes of illustrating embodiments of thepresent disclosure and not for purposes of limiting the same.

DETAILED DESCRIPTION

Various techniques are provided to facilitate the use of nanostructuresto monitor (e.g., evaluate, validate) an additive manufacturing process.Additive manufacturing may be utilized to form layers through use ofmaterial deposition, laser deposition, laser heating, magnetic heating,and/or other processes for depositing materials and aligning polymers(e.g., through curing operations). In some embodiments, thenanostructures are distributed in material(s) deposited in an additivemanufacturing process to facilitate monitoring of the process. Thenanostructures may be mixed with (e.g., integrated into) the depositionmaterial(s) and then deposited along with the deposition material(s) toform layers of an object (also referred to as a product). The object maybe a part of an aircraft, an antenna, and/or generally any objectamenable to manufacturing using an additive manufacturing process.

The nanostructures include a quantum dot (also referred to as a core ora quantum dot core) and at least one shell encompassing the quantum dot.For example, the nanostructures can be provided in a lattice-typestructure in the deposited material(s). In some cases, the shell(s) ofthe nanostructures may be doped, e.g. with metal material, prior tobeing mixed with the deposition material(s). Energy coupling mechanismssuch as Førster resonance energy transfer (FRET) may be utilized tofacilitate the binding of the nanostructures with one another andbinding of a quantum dot to the encompassing shell. In general, thenanostructures are configured (e.g., designed, formed, fabricated) suchthat the properties of the material(s) deposited in the manufacturingprocess and an object formed by the manufacturing process are notaffected by the presence of the nanostructures or components thereof(e.g., quantum dots, shells). The nanostructures may beone-part-per-million or less (e.g., by weight) relative to thedeposition material(s).

Electrons within the quantum dots and the shells can absorb energy, suchas electricity, sunlight, heat, microwaves, or electromagnetic (EM)radiation, and emit energy (e.g., as EM radiation or as a current) inresponse. In an embodiment, a layer of material(s) with thenanostructures distributed therein is excited by EM radiation and emitsEM radiation in response. When an excitation signal (e.g., EM radiation)associated with energy higher than the band gap of the nanostructures isapplied to the nanostructures, the excitation signal is absorbed by thenanostructures and a signal is emitted (e.g., via fluorescence). Theemitted signal has an energy that is based on the band gap of thenanostructures. Equivalently, as the emitted signal's wavelength isinversely proportional to the emitted signal's energy, the emittedsignal has a wavelength based on the band gap of the nanostructures. Theemitted signal has a lower energy (or equivalently a higher wavelength)than the excitation signal. The excitation signal and the emitted signalmay have wavelengths in the visible light region, infrared region,ultraviolet (UV) region, and/or generally any wavelength suitable forexcitation and/or detection (e.g., of the emitted signal).

The quantum dot and its encompassing shell generally include differentmaterials and exhibit different properties, such as different meltingpoints and band gaps. In this regard, the dopants of the shell may beutilized to tune the wavelength of the emitted signal from the shell.Thus, when the shells are intact, the excitation signal is absorbed bythe shells and a signal that has a wavelength associated with the bandgap of the shells is emitted. In this case, the quantum dots of thenanostructures are blocked from the excitation signal by theirencompassing shells and/or an emitted signal from the quantum dots inresponse to any portion of the excitation signal received by the quantumdots is blocked by the shells. When the shells are removed (e.g.,melted, dissolved, deactivated) and the quantum dots are intact, theexcitation signal is absorbed by the now exposed quantum dots and asignal that has a wavelength associated with the band gap of the quantumdots is emitted. In this regard, the removal of the shell and associatedexposing of the interior quantum dot can be referred to as fluorescentactivation of the quantum dot.

As used herein, the wavelength of the excitation signal is representedby λ₁ and the wavelength of the emitted signal from a shell and aquantum dot are represented by λ₂ and λ₃, respectively. In anembodiment, as the nanostructures distributed in the deposited materialare generally not completely identical (e.g., size and/or shape are notuniform), λ₂ and λ₃ may represent a range of wavelengths that may beassociated with the shell and quantum dot, respectively. In some cases,λ₁ may also represent a range of wavelengths. The wavelengths at whichthe quantum dot and the shell fluoresce are generally selected to be farenough apart that they can be distinguished from each other. In somecases, when the wavelengths are in the visible-light spectrum, emissionsof the quantum dots and the shells can be observed as different colors.

In an embodiment, the detected emitted signal can be associated withmanufacturing characteristics of manufacturing operations performed inthe manufacturing process to facilitate monitoring of the manufacturingprocess. The manufacturing operations may include heating operations,pressurizing operations, curing operations, and/or other operations tomanufacture the object. The various operations may be utilized, forexample, to enhance the structural integrity (e.g., harden, toughen) ofthe deposited material(s) (e.g., and the completed object by extension),such as by cross-linking of polymer chains in the deposited material,and/or define other properties of the object. The manufacturingoperations may be associated with manufacturing operations, such as aspecified temperature and/or specified pressure to be reached.

For example, a manufacturing operation may be a curing operationperformed at a specified temperature. In this regard, the manufacturingcharacteristic of the curing operation may be, or may include, thespecified temperature that needs to be reached. The shells may beconfigured to be removed and the quantum dots configured to remainintact when the specified temperature has been reached.

In this example, the nanostructures may be utilized to determine whetherthe curing operation is properly performed (e.g., performed at thespecified temperature). Using the emitted signal from nanostructuresdistributed in the deposition materials, the specified temperature canbe determined to have been reached (e.g., the manufacturingcharacteristic can be determined to have been satisfied) based onwavelength components contained in the emitted signal. For example, thepresence of the wavelength component associated with the quantum dots inthe emitted signal and lack of presence of the wavelength componentassociated with the shells in the emitted signal are indicative of theshells of the nanostructures having been removed. In turn, the shellshaving been removed may indicate that the specified temperature has beenreached. In some cases, an intensity, or any other measure of powertransferred per unit area or volume, of the wavelength components (e.g.,of the quantum dots and shells) can be utilized to make thedetermination.

Thus, using various embodiments, the additive manufacturing process canbe monitored (e.g., in real time) as each layer of material withnanostructures distributed therein is found. An excitation signal may beapplied to at least a portion of the layer and an emitted signaldetected from the portion of the layer to which the excitation signalwas applied. A manufacturing characteristic (e.g., temperature,pressure, pH level) associated with a manufacturing operation can bedetermined to have been satisfied or not satisfied based at least on thewavelength of the emitted signal. In this regard, in cases that themanufacturing operation is utilized to enhance cross-linking of polymersin the object, the manufacturing characteristic not having beensatisfied may indicate a potential flaw in the deposited layer, such asimproper or insufficient cross-linking of the polymers that mayultimately lead to a defective final product.

When a potential flaw is detected, the manufacturing process may beinterrupted. Information associated with a potential flaw can be caughtin-process with minimal latency and fed back for processing, such asmanually by an operator (also referred to as a user) of themanufacturing process and/or autonomously by a computing device.Additional analysis may be utilized to verify that the flaw exists anddetermine regions/portions of the deposited layer that exhibit the flaw.Depending on the application and situation, in some cases, themanufacturing process can be adjusted to allow repair of the depositedlayer or regions/portions of the deposited layer associated with theflaw. In other cases, the manufacturing process can be ended and theobject discarded.

Accordingly, the manufacturing process can be evaluated in-process asthe layers are found and manufacturing operations are performed on thelayers, and the manufacturing process adjusted to fix any potentialflaws as they arise and/or end the manufacturing process. In thisregard, costs and resources (e.g., of material(s) and time) can bereduced. For example, costs associated with obtaining the informationand determining whether to proceed with the manufacturing process (e.g.,with or without adjusted parameter values) may be lower thanmanufacturing a defective final product that needs to be discarded andneeding to perform a new manufacturing process to manufacture theproduct. In some cases, minimal or no post-process NDE is performed onthe completed product, thus reducing associated cost and complexity.

In an embodiment, not all of the deposited layers are evaluated. In somecases, these deposited layers do not have nanostructures distributedtherein. In other cases, these deposited layers may have nanostructuresdistributed therein. For example, in these latter cases, the cost (e.g.,time cost, component cost) and/or complexity associated withdistributing nanostructures in the deposited material of some layers andnot in other layers may be higher than distributing nanostructures inall deposited layers of material.

Referring now to the drawings, FIG. 1 illustrates a system 100 for usingnanostructures to monitor a manufacturing process in accordance with anembodiment of the present disclosure. The system 100 includes acomputing device 105, an additive manufacturing device 110, anexcitation device 115, and a detection device 120. In an embodiment, themanufacturing process is an additive manufacturing process, in which amaterial(s) is deposited layer-by-layer to form an object 125.

The computing device 105 performs operations to facilitate performingand monitoring of the manufacturing process. In particular, thecomputing device 105 may perform operations to define, coordinate,and/or adjust the manufacturing process and associated monitoringprocess (e.g., evaluating process) as appropriate. The computing device105 may be electronically coupled (e.g., wired and/or wirelessly) to theadditive manufacturing device 110, excitation device 115, and detectiondevice 120 to facilitate communication, e.g. for the computing device105 to transmit commands and/or information to the devices 110, 115,and/or 120 and receive information from the devices 110, 115, and/or120.

The computing device 105 may generate initial parameter values for themanufacturing process and provide these values to the additivemanufacturing device 110, excitation device 115, and/or detection device120. The initial parameter values may specify parameters to use toperform the manufacturing process and the monitoring process. In somecases, the initial parameter values may be set based on values (e.g.,empirical values) previously determined for a similar application and/orobject, and/or provided manually by the user.

The computing device 105 may provide instructions to the devices 110,115, and 120 to perform specified functions based on the initialparameter values. For example, the computing device 105 may provideinstructions to the additive manufacturing device 110 to start themanufacturing process (e.g., start depositing a first layer ofmaterial), the excitation device 115 and detection device 120 toevaluate a deposited layer of material, and/or other instructions. Insome cases, the initial parameter values may indicate when the devices110, 115, and/or 120 are to perform the specified functions. In anembodiment, the computing device 105 may provide instructions to thedevices 110, 115, and/or 120 that override previously providedinstructions. The new instructions may be generated in response topotential problems arising in the manufacturing process, such as aspecified temperature not being reached for a curing operation. In thisregard, the new instructions may adjust parameter values to be used inthe manufacturing process or may terminate the manufacturing process.

In an embodiment, to facilitate in-process monitoring of themanufacturing process, the computing device 105 may determine whethermanufacturing characteristics associated with manufacturing operationsof the manufacturing process are being satisfied and perform operationsaccordingly based on the determination. For example, a manufacturingoperation may include applying a heating operation (e.g., an annealingoperation) on a formed layer (e.g., deposited layer) of material. Amanufacturing characteristic of the heating operation may be atemperature that needs to be reached by the heating operation. In thisexample, when the manufacturing characteristic is determined to besatisfied (e.g., specified temperature is reached), the computing device105 may allow the manufacturing process to continue as previouslyspecified. However, when the manufacturing characteristic is determinedto not be satisfied, the computing device 105 may interrupt themanufacturing process and perform actions to address the situation.

When the manufacturing characteristic is determined to not be satisfied,the computing device 105 may determine that a potential flaw exists andperform additional analysis to verify the flaw and determineregions/portions of the formed layer that exhibit the flaw. Depending onthe application and situation, in some cases, the computing device 105may adjust the manufacturing process to allow repair of the depositedlayer or specific regions/portions thereof. In other cases, thecomputing device 105 may end the manufacturing process. In some cases,the computing device 105 may request and/or receive input from the userregarding whether to or how to proceed.

In an embodiment, the computing device 105 may control one or moreimaging devices, such as visible-light or infrared cameras, that may beutilized to capture images or provide a video feed of the depositionmaterial to the user. The imaging devices may be of any physical size,spectral bandwidth, and/or resolution as appropriate to facilitatemonitoring of the manufacturing process. Some or all of the imagingdevices may be separate from the computing device 105.

In some cases, the imaging devices may be utilized to capture imageand/or video data (e.g., visible-light, infrared, and/or otherwavelengths) throughout the manufacturing process. For example, theimaging devices may be utilized to capture images or provide a videofeed of the object to the user as the layers are deposited to allow realtime inspection. In other cases, the imaging device may be utilizedprimarily when the manufacturing characteristic is determined to nothave been satisfied, e.g. to conserve power and resources until apotential problem has been detected. The imaging devices may becalibrated to facilitate dimensional analysis of the object, such as todetermine whether a layer of deposited material is of a desiredthickness. Information from the imaging devices may be utilized tosupplement information from the detection device 120.

The additive manufacturing device 110 includes components utilized toimplement the manufacturing process to manufacture the object 125. Theadditive manufacturing device 110 may include one or more printingnozzles (also referred to as dispense heads) to hold and dispensematerial to be deposited. In some cases, the additive manufacturingdevice 110 may include multiple print nozzles, where different printingnozzles may, but need not, hold different material to be deposited. Theprint nozzle(s) may be movable and/or rotatable to facilitate depositingof material(s) at different locations. The printing nozzles may beswappable, such that a printing nozzle may be removed and replaced withanother printing nozzle, e.g. to replace a printing nozzle determined tobe defective. The printer nozzle(s) may be lowered when in operation andraised when not in use. In an embodiment, the printing nozzle(s)contains material that includes nanostructures distributed therein to bedeposited.

The additive manufacturing device 110 may include a substrate (alsoreferred to as a deposition surface) onto which layers of material maybe deposited. In some cases, the substrate may be a separate componentfrom the additive manufacturing device 110 that is useable (e.g.,compatible) with the additive manufacturing device 110 to facilitateimplementation and possibly monitoring of the manufacturing process(e.g., by repositioning the object 125 to facilitate analysis). Thesubstrate is generally configured to provide support to hold thedeposited layers and adapt to changes in the deposition layers (e.g.,hardening) throughout the manufacturing process.

In some cases, the substrate may be movable and/or rotatable along atleast some dimensions. In other cases, the substrate may be fixed. Thesubstrate may have a heated/heatable surface that can be used to heatthe layers of material deposited on the substrate, such as to allowcontrol of a drying time of the deposited layers. The temperature usedto heat the deposition material may be adjustable. The substrate mayhave a vacuum surface. The vacuum surface may be used to apply a vacuumsuction to the layers of material deposited on the substrate to hold thelayers in place during the manufacturing process.

The additive manufacturing device 110 may implement the manufacturingprocess based on the initial parameter values and/or other instructionsfrom the computing device 105. By way of non-limiting example, theinitial parameter values for the additive manufacturing device 110 mayidentify (e.g., specify) material(s) for the nanostructures (e.g.,quantum dots, shells, and dopants), material(s) to be used for eachlayer, number and dimensions (e.g., length, width, and/or thickness) ofeach layer, start and/or end time for forming each layer, manufacturingoperations (e.g., heating operations, curing operations) to be performedon each layer and associated characteristics (e.g., pressure,temperature, pH level), and/or other parameters. In addition, theinitial parameter values for the additive manufacturing device 110 mayidentify characteristics to operate specific components of the additivemanufacturing device 110, such as flow rate of material deposited by theprinting nozzle, temperature of the printing nozzle, temperature of thesubstrate, pressure applied to the substrate, vertical distance betweena dispense tip of the printer nozzle and the substrate, and/or otherparameters. For example, when the manufacturing begins, the additivemanufacturing device 110 may release a material from the printingnozzle(s) at a flow rate and a temperature specified by the initialparameter values.

The excitation device 115 may apply an excitation signal to a layer(s)of deposited material. The excitation device 115 may be, or may include,one or more light sources, such as laser light sources, that can applyan optical signal to the layer(s) of deposited material. The excitationsignal may be EM radiation at a specified wavelength. By way ofnon-limiting example, the initial parameters for the excitation device115 may include a wavelength or wavelength range of the excitationsignal and a position/orientation of the excitation device 115 (e.g.,relative to the deposited material).

The detection device 120 may receive (e.g., detect) a signal emitted bythe layer(s) of deposited material in response to the excitation signalfrom the excitation device 115. The emitted signal may be a feedback EMradiation. In some embodiments, the emitted signal received by thedetection device 120 may be emissions from the nanostructuresdistributed in the layer(s) of deposited material in response to theexcitation signal from the excitation device 115. By way of non-limitingexample, the initial parameter values for the detection device 120 mayinclude a wavelength or wavelength range of the emitted signal from thenanostructures (e.g., from quantum dots and/or shells) and aposition/orientation of the detection device 120 relative to thedeposited material. In this regard, the detection device 120 may beconfigured (e.g., calibrated) to be sensitive to a range of fluorescentexcitation emitted by the nanostructures (e.g., quantum dots, shells).The emitted signal may have wavelengths in the visible light region,infrared region, UV region, and/or generally any wavelength suitable fordetection. The detection device 120 may be an optical device fordetecting light of certain wavelengths, a boroscope designed forsensitivity to wavelengths of light in an appropriate range, aspectroscopy device, a photo-spectroscopy device, a combination thereof,and/or any other device known or available in the art for detectingwavelengths of light or signals emitted by the quantum dots and/orshells.

In some cases, the detection device 120 may include a processor forprocessing data regarding emissions by the nanostructures gathered bythe detection device 120 and a memory for storing the data.Alternatively or in addition, in some cases, the detection device 120may also include a network device for transmitting data, such as dataregarding wavelengths emitted by the nanostructures, over a network to aremote computing device (e.g., the computing device 105) for processing.In this regard, the computing device 105 and/or the detection device 120may be utilized to determine information about the emitted signal, suchas locations from which the emitted signal is received, wavelengthcomponents contained in the emitted signal, intensities associated withthe wavelength components, and/or any additional information regardingthe emitted signal. The information may be presented in the form of anintensity mapping that identifies locations on the layer(s) of depositedmaterial and associated intensity levels for the wavelength componentsemitted from the identified locations.

To facilitate efficiency of implementing the manufacturing process, thedevices 105, 110, 115, and 120 may adjust the initial parameter valuesas needed to accommodate for slight variations in conditions due toambient temperature and/or pressure. For example, the initial parametervalues may specify the ambient temperature and/or pressure dependencefor which the various initial parameter values were computed. Theinitial parameter values may be adjusted accordingly in response to theactual ambient temperature and/or pressure or variations therein at thetime of the manufacturing process. For example, the additivemanufacturing device 110 may autonomously and adaptively adjust flowrates of the printing nozzles as the ambient temperature and/or pressurechanges throughout the manufacturing process.

FIG. 2 illustrates block diagram of the computing device 105 forfacilitating a manufacturing process and monitoring (e.g., evaluating)the manufacturing process in accordance with an embodiment of thepresent disclosure. Although a variety of components are illustrated inFIG. 2, additional, fewer, and/or different components may be providedas appropriate in various embodiments. As shown in FIG. 1, the computingdevice 105 may be utilized with the additive manufacturing device 110,excitation device 115, and detection device 120.

The computing device 105 includes user controls 205, a display 210, aprocessor 215, and a memory 220. The user controls 205 may includebuttons, switches, and/or dials that can be used to set or adjustvarious settings and/or parameters, e.g. by pushing buttons, flippingswitches, and/or turning dials. In some cases, the user controls 205 mayinclude a keyboard, virtual keyboard, touch screen, mouse, and/or otherinput device or capability coupled to and/or provided by the computingdevice 105 to allow user input to the computing device 105.

The display 210 may include a flat screen display or a touch screendisplay. The display 210 may be utilized to display informationassociated with the manufacturing process to the user. For example, thecomputing device 105 may receive information from the detection device120 and/or derive information based on information received from thedetection device 120 regarding the emitted signal detected by thedetection device 120, such as presence of different wavelengthcomponents, intensity levels of different wavelength components, and/orlocations of the deposited material from which the various wavelengthcomponent are emitted. The computing device 105 may provide suchinformation for display to the user via the display 210, such as uponrequest by the user. In some cases, prompts may be displayed to the userto request user input, such as requesting instructions on whether toproceed with a manufacturing process. Alternatively or in addition, thecomputing device 105 may transmit the information to a user device(e.g., mobile phone) to be displayed by the user device. The informationmay be transmitted in a short message service (SMS) text message and/oran email for example.

In some cases, the user controls 205 may be integrated with and may alsobe a part of the display 210. For example, the display 210 may be atouch screen display on which a user interface including the usercontrols 205 may be presented and used by the user. The user may adjustvarious settings and/or parameters by touching the user interfacemonitor set or adjust various settings and/or parameters, and/orotherwise controlling the manufacturing process and/or monitoring of themanufacturing process. In other cases, the user controls 205 may be aseparate component from the display 210.

The processor 215 may be implemented as one or more microprocessors,microcontrollers, application specific integrated circuits (ASICs),programmable logic devices (PLDs) (e.g., field programmable gate arrays(FPGAs), complex programmable logic devices (CPLDs), field programmablesystems on a chip (FPSCs), or other types of programmable devices),codecs, and/or other processing devices.

In some embodiments, the processor 215 may execute machine readableinstructions (e.g., software, firmware, or other instructions) stored inthe memory 220. In this regard, the processor 215 may perform any of thevarious operations, processes, and techniques described herein. Forexample, in some embodiments, the various processes and subsystemsdescribed herein (e.g., additive manufacturing device controlapplication 260, detection device control application 270) may beeffectively implemented by the processor 215 executing appropriateinstructions. In other embodiments, the processor 215 may be replacedand/or supplemented with dedicated hardware components to perform anydesired combination of the various techniques described herein.

The memory 220 may be implemented as a machine readable medium storingvarious machine readable instructions and data. For example, in someembodiments, the memory 220 may store an operating system 225 andapplications 255 as machine readable instructions that may be read andexecuted by the processor 215 to perform the various techniquesdescribed herein. The memory 220 may also store data used by theoperating system 225 and/or applications 255. In an embodiment, thememory 220 may be implemented as non-volatile memory (e.g., flashmemory, hard drive, solid state drive, or other non-transitory machinereadable mediums), volatile memory (e.g., random access memory), orcombinations thereof.

In FIG. 2, the memory 220 stores initial parameter values 230. Theinitial parameter values 230 may be provided to the additivemanufacturing device 110 to implement an associated manufacturingprocess. The memory 220 adjusted parameter values 235. The adjustedparameter values 235 may include adjustments made to the initialparameter values 230 and/or adjustments made to previously adjustedparameter values (e.g., multiple adjustments to the same parameter). Insome cases, the adjusted parameter values 235 may also include a changehistory that identifies any changes made to the initial parameter values230 and any further changes to the adjusted parameter values, such as toallow the adjustments to be analyzed to facilitate the generation andimplementation of future manufacturing and/or associated monitoringprocesses.

The memory 220 stores detected emission data 240. The emission data 240may be obtained from the detection device 120 and/or derived frominformation obtained from the detection device 120. The emission data240 may include an intensity mapping that provides presence of differentwavelength components, intensity levels of different wavelengthcomponents, and/or locations of the deposited material from which thevarious wavelength component are emitted.

The memory 220 stores a material property database 245. The materialproperty database 245 may be a compilation of information from materialshandbooks. The information may include material properties, such ascomposition, specific heat, density, band gap, melting/freezing point,condensation/vaporization point, and/or other information for variousmaterials. The information may be used as reference by the user and/orone or more of the applications 255 to facilitate selection of thematerials to be used to form the object 125 and/or the nanostructuresand/or perform computations based on material properties. The memory 220may store the materials handbooks themselves and/or may storeinformation (e g, links, access information, etc.) to access thematerials handbooks (e.g., online or cloud sources).

Other data 250 may include any information that may be utilized todefine, coordinate, and/or adjust the manufacturing process andassociated monitoring process (e.g., evaluating process) as appropriate.For example, other data 250 may include image and/or video data (e.g.,visible-light, infrared, and/or other wavelength) taken during themanufacturing process. The image/video data may be processed todetermine a smoothness/roughness of different portions of the depositedlayer(s), dimensions of the deposited layer(s), a temperature associatedwith different portions of the deposited layer(s), and/or othercharacteristics of the object.

The applications 255 may include applications for facilitatingimplementation of a manufacturing process and/or monitoring of themanufacturing process, and/or adjustments to these processes. In FIG. 2,the applications 255 include an additive manufacturing device controlapplication 260, an excitation device control application 265, adetection device control application 270, an object/process analysisapplication 275, and other applications 280 that are not necessarilyprovided herein. In some cases, the applications 255 may be executed bythe processor 215 of the computing device 105.

The processor 215 may utilize the additive manufacturing device controlapplication 260 to provide commands to the additive manufacturing device110 or components thereof (e.g., substrate, printing nozzle). Theadditive manufacturing device control application 260 may implement themanufacturing process based on the initial parameter values 230 and/oradjusted parameter values 235. The additive manufacturing device controlapplication 260 may generate commands to pause or end the manufacturingprocess in response to user input or an error being detected (e.g., amanufacturing characteristic not having been satisfied). In some cases,the commands may be generated in response to user input (e.g., commandsreceived from the user via the user controls 205). In other cases, thecommands may be automated commands generated by the additivemanufacturing device control application 260.

The processor 215 may utilize the excitation device control application265 to control operation of the excitation device 115. The excitationdevice control application 265 may set the excitation wavelength,location(s) of the deposited layer(s) of material at which to apply theexcitation signal(s), and/or placement and/or orientation (e.g., angleat which transmitter of excitation signal is pointed) of the excitationdevice 115. In some cases, the excitation device control application 265may control movement and/or orientation of the excitation device 115,such as to apply an excitation signal to different portions of thedeposited layer(s) of material. The processor 215 may utilize thedetection device control application 270 to control operation of thedetection device 120. The detection device control application 270 mayidentify the wavelength(s) to detect, and/or placement and/ororientation of the detection device 120 to facilitate detection of theemitted signal. In some cases, the detection device control application270 may operate in tandem with the excitation device control application265 to control movement and/or orientation of the detection device 120,such as to receive the emitted signal in response to excitation signalsapplied to different portions of the deposited layer(s) of material.

The processor 215 may utilize the object/process analysis application275 to monitor a manufacturing process (e.g., in real time) and/oranalyze a previously performed manufacturing process. The object/processanalysis application 275 may utilize the initial parameter values 230,adjusted parameter values 235, detected emission data, material propertydatabase 245, and/or other data 250 (e.g., image/video data) todetermine properties of the object being formed. For example, theobject/process analysis application 275 may be utilized to obtaininformation associated with the manufacturing and/or monitoringprocesses and/or determine how or whether to adjust the manufacturingand/or monitoring processes, such as in response to an error beingdetected (e.g., a manufacturing characteristic not having beensatisfied). The object/process analysis application 275 may also beutilized to analyze successful and failed manufacturing processes tofacilitate generation of future manufacturing and/or monitoringprocesses.

Other applications 280 may include any other application to facilitatedefining and/or implementing the manufacturing and/or monitoringprocesses. The other applications 280 may include, for example, animaging application. The imaging application may be utilized to captureand process image and/or video data associated with the manufacturingprocess. The data may be utilized to visually inspect the object duringthe manufacturing process and/or in response to an error being detected.

FIG. 3 illustrates nanostructures in layers of an object 300 inaccordance with an embodiment of the present disclosure. In anembodiment, the object 300 may be formed using the system 100 of FIG. 1.As part of a manufacturing process, layers 305 and 310 have been formed.A layer 315 is formed over the layers 305 and 310. For example, theadditive manufacturing device 110 may deposit the layer 315 over thelayers 305 and 310. The layers 305, 310, and 315 include a material 320,325, and 330, respectively, and nanostructures distributed therein. Asan example, a nanostructure 335 in the layer 305, a nanostructure 340 inthe layer 310, and nanostructures 345 and 350 in the layer 315 areexplicitly labeled in FIG. 3. The material 320, 325, and 330 may bereferred to as a bulk material of their respective layers.

As part of the manufacturing process, a manufacturing operation(s) maybe performed on the layers that are formed. A manufacturing operationmay be associated with one or more manufacturing characteristics to besatisfied. For example, a curing operation applied on the layer 315 maybe associated with a specified temperature and/or specified pressure tobe reached in order properly cure the layer 315. In variousapplications, the specified temperature may be a temperature withinaround 200° F. and 500° F.

An evaluation of the layer 315 may be based on evaluating whether themanufacturing characteristic(s) of the manufacturing operation(s)performed on the layer 315 has been satisfied. In an embodiment, toevaluate the layer 315, an excitation signal of wavelength 2 may beapplied to the layer 315, e.g. by the excitation device 115. In responseto the excitation signal of wavelength λ₁, nanostructures (e.g., 345,350) in the layer 315 may emit a signal. The emitted signal may bedetected by the detection device 120 and may have wavelength componentsλ₂ and λ₃. Nanostructures with their shells intact, such as thenanostructure 345, may emit a signal of wavelength λ₂ in response to theexcitation signal. Nanostructures with their shells removed, such as thenanostructure 350, may emit a signal of wavelength λ₃.

In an embodiment, the nanostructures are configured such that the shellsare removed and the quantum dots remain intact when the manufacturingcharacteristic(s) of the manufacturing operation(s) has been satisfied.The determination of whether the manufacturing characteristic(s) hasbeen satisfied may be performed (e.g., by the computing device 105)after a predetermined amount of time has passed. For example, thepredetermined amount of time may be the time determined to be sufficientto complete the manufacturing operation (e.g., curing operation). Thedetermination may be based on a threshold(s) set for the intensity ofthe λ₂ and/or λ₃ components (e.g. set as part of the initial parametervalues) of the signal emitted from the layer 315 in response to theapplied excitation signal. In this regard, since the shells areconfigured to be removed when the manufacturing characteristic(s) issatisfied, the quantum dots are exposed to the excitation signal tocause the quantum dots to emit a signal of wavelength λ₃ when themanufacturing characteristic(s) is satisfied. For instance, themanufacturing characteristic(s) may be considered to have been satisfiedwhen the intensity of the λ₂ component is below a first threshold andwhen the intensity of the component is above a second threshold.

As examples, the manufacturing characteristic(s) is considered to nothave been satisfied when the emitted signal from the layer 315 has a λ₂component of higher intensity than the first threshold (e.g., a largepercentage of the shells have not been removed), when no emitted signalis received (e.g., the quantum dots and shells have been dissolved orotherwise deactivated), and/or otherwise when the emitted signal doesnot include a λ₃ component of sufficient intensity.

In an embodiment, an evaluation process may be performed on each layerthat is formed. In FIG. 3, prior to forming the layer 315, the layer 305and/or 310 may have been evaluated using a similar evaluation process.In this regard, the nanostructures (e.g., 335, 340) of the layers 305and 310 are depicted as having only the quantum dots intact, e.g. theshells have been removed by a manufacturing operation(s). In anotherembodiment, an evaluation process is not performed for each layer thatis formed.

FIG. 4 illustrates forming of a layer of an object and evaluating thelayer in accordance with an embodiment of the present disclosure. In anembodiment, the layer of the object is forming using the system 100 ofFIG. 1. In this embodiment, the additive manufacturing device 110 mayinclude a substrate 405 and printing nozzle 410. In some cases, theadditive manufacturing device 110 may include additional components,such as additional printing nozzles and/or control circuitry. Forexample, additional printing nozzles may allow faster depositing of thelayer(s) of material and/or depositing of different materials within alayer or in different layers (e.g., different printing nozzles depositdifferent materials). The control circuitry may generate signals tocontrol the operation of the additive manufacturing device 110 and maybe based on initial parameter values and/or instructions from thecomputing device 105. Control signals may be utilized to control flowrate and/or temperature of the printing nozzle 410, temperature and/orpressure applied to the substrate 405, adjustment in position and/ororientation of the substrate 405 and/or printing nozzle 410, and/orother aspects associated with the additive manufacturing device 110. Theprinting nozzle 410 forms the layer by depositing (e.g., printing)portions of the layer, where each portion is represented as a sphere inFIG. 4. In general, to facilitate evaluating the layer, each portion mayinclude the deposition material and nanostructures distributed therein.

In an embodiment, a manufacturing operation is performed on depositedportions of the layer. For example, in FIG. 4, a laser 415 and opticalelements 420 (e.g., lenses, mirrors) can be utilized to perform a curingoperation (e.g., laser curing operation). The laser 415 transmits alaser with a wavelength appropriate for the curing operation (e.g., UVwavelength for UV curing) and the optical elements 420 direct the laserto a previously formed portion 435 of the layer to be cured. In somecases, operation of the laser 415 and optical elements 420 may bespecified by the computing device 105 (e.g., in the initial parametervalues). In some cases, the laser 415 and/or the optical elements 420may be movable and/or rotatable to allow different portions of the layerto be cured using the laser 415 and the optical elements 420.Alternatively or in addition, additional lasers and/or optical elementsmay be utilized to cure different portions of the layer.

To evaluate portions of the layer, the excitation device 115 applies anexcitation signal to the portions of the layer and the detection device120 detects an emitted signal from these excited portions. For example,in FIG. 4, the excitation device 115 applies an excitation signal to aportion 430 of the layer and the detection device 120 detects an emittedsignal from the portion 430. The emitted signal is provided by at leasta subset of nanostructures distributed in the portion 430 of the layer.The excitation signal may have a wavelength λ₁. In response to theexcitation signal of wavelength λ₁, the emitted signal may have awavelength λ₂ (e.g., emitted by nanostructures with at least a portionof their shells intact) and/or a wavelength λ₃ (e.g., emitted by fornanostructures with at least a portion of their shells removed). Thewavelengths λ₂ and λ₃ are selected such that the detection device 120can readily distinguish between a λ₂ component of the emitted signalfrom a λ₃ component of the emitted signal.

As shown in FIG. 4, in some cases, a portion 440 is being formed by theprinting nozzle 410 while a previously formed portion (e.g., 430) isbeing evaluated and another previously formed portion (e.g., 435) isbeing cured. Since different parts of the manufacturing and monitoringprocesses are performed in parallel, such an implementation may allowefficient manufacturing of the object. To allow such an implementation,the manufacturing process is designed to avoid interference betweenforming, curing, and evaluating of respective portions of the layer. Forexample, to allow simultaneously curing and evaluating the layer, thewavelength(s) associated with the laser curing is selected to notinterfere with the wavelength(s) of the excitation signal and theemitted signal, and/or vice versa. When the wavelength(s) may interfere,the laser 415 may be turned off when the excitation signal is applied,and vice versa. In other manufacturing processes, an entire layer may beformed prior to a manufacturing operation and/or evaluation operationbeing performed.

In some cases, the excitation device 115 may excite multiple portions ofthe formed layer simultaneously. For example, the excitation device 115may include and/or may utilize (e.g., control) multiple excitationsources to excite multiple portions of the layer(s) at a time. Thedetection device 120 may include appropriate sensors to capture to theemitted signals from the excited portions.

FIG. 5 illustrates different signals emitted by an object 500 inresponse to an excitation signal in accordance with an embodiment of thepresent disclosure. The object 500 may be completed or partiallycompleted. The object 500 may be formed by adding one layer on top ofanother. In FIG. 5, an excitation signal of wavelength λ₁ are applied toa side of the object 500 (e.g., rather than a top surface of the object500). In response to the excitation signal, a portion 505 of the object500 emits a signal of wavelength λ₂ and a portion 510 of the object 500emits a signal of wavelength λ₃. Thus, an evaluation of the object 500may indicate that a manufacturing characteristic(s) of a manufacturingoperation(s) applied to the portion 505 was not satisfied, whereas amanufacturing characteristic(s) of a manufacturing operation(s) appliedto the portion 510 was satisfied. For example, an emission with a highintensity of λ₂ components may indicate a poor diffusion bondingprocess, whereas an emission with a high intensity of λ₃ components mayindicate a proper diffusion bonding process. In some cases, furtheranalysis of the portions 505 and 510 and/or other portions may beutilized to verify the indication.

In FIG. 5, multiple deposited layers of the object 500 may be evaluatedusing the excitation signal. Such an excitation may be performed as analternative to or in addition to evaluating each layer as the layer isformed (e.g., deposited). For example, the excitation may be performedon the completed product, e.g. as a final check on the manufacturingprocess. Depending on application, in some cases, evaluating only asubset of the deposited layers may expedite the manufacturing of acompleted object and save on manufacturing costs (e.g., less time andpower consumed).

FIG. 6A illustrates an example of a nanostructure 600 in accordance withan embodiment of the present disclosure. The nanostructure 600 includesa quantum dot 605 and a shell 610 encompassing the quantum dot 605. Thequantum dot 605 may include silicon, germanium, gallium, arsenide,indium phosphide, cadmium selenide, zinc sulfide, other substances,and/or a combination thereof. The shell 610 may include silicon, cadmiumselenide, cadmium sulfide, cadmium telluride, and/or other elemental orcompound semiconductors. In an embodiment, the shell 610 may be dopedwith a metal, such as sodium or tin, or metal alloy.

The quantum dot 605 and the shell 610 may each have a band gap. With theshell 610 intact, when an excitation signal (e.g., EM radiation)associated with energy higher than a band gap of the shell 610 isapplied to the shell 610, the excitation signal is absorbed by the shell610 and a signal is emitted. The emitted signal has a lower energy thanthe excitation signal. Equivalently, as the emitted signal's wavelengthis inversely proportional to the emitted signal's energy, the emittedsignal has a larger wavelength than the excitation signal. In FIG. 6A,the wavelength of the excitation signal is represented by λ₄ and thewavelength of the emitted signal from the shell 610 is represented byλ₂. When the shell 610 is intact, the quantum dot 605 is not exposed. Inan embodiment, when the shell 610 is intact, the quantum dot 605 isblocked from the excitation signal by the shell 610 and/or an emittedsignal of the quantum dot 605 (e.g., in response to any portion of theexcitation signal received by the quantum dot 605) is blocked by theshell 610.

In an embodiment, nanostructures, such as the nanostructure 600, may bedistributed throughout (e.g., impregnated in) a material that isdeposited as part of a manufacturing process (e.g., additivemanufacturing process). In this embodiment, at various stages of themanufacturing process, the shell 610 of the nanostructure 600 maydissipate, dissolve, or otherwise be removed. For example, the shell 610may be removed when the shell 610 reaches a certain temperature,pressure, and/or pH level (e.g., in response to a manufacturingoperation that is performed). Once the shell 610 is removed, the quantumdot 605 is exposed.

FIG. 6B illustrates an example of the nanostructure of FIG. 6A with theshell partially removed in accordance with an embodiment of the presentdisclosure. When the shell is partially removed, remaining portions ofthe shell 610 may emit a signal of wavelength λ₂ in response to theexcitation signal of wavelength λ₁ and portions (e.g., exposed portions)of the quantum dot 605 may emit a signal of wavelength λ₃. In anembodiment, the shell 610 may be partially removed while a manufacturingoperation(s) (e.g., heating operation, pressurizing operation, curingoperation) is being performed on the nanostructure.

FIG. 6C illustrates an example of the nanostructure of FIG. 6A with theshell completely removed in accordance with an embodiment of the presentdisclosure. When the shell is completely removed, the excitation signalof wavelength λ₁ causes the quantum dot 605 to emit a signal ofwavelength λ₃. In an embodiment, the shell 610 may be completely removed(or mostly completely removed) when the manufacturing characteristic(s)of the manufacturing operation(s) has been satisfied, e.g. the specifiedtemperature of the curing operation has been reached. In this regard, adetermination as to whether the manufacturing characteristic(s) has beensatisfied may be based at least in part on the presence (or lack ofpresence) of a signal emitted by the quantum dot 605 and/or a signalemitted by the shell 610.

Quantum dots (also be referred to as semiconductor nanocrystals orsemiconductor nanostructures) are tiny crystals that may have sizes onthe order of nanometers and may include a few hundred to a few thousandsof atoms. For example, a spherical or substantially spherical quantumdot may be less than 100 nanometers in diameter. In some applications,quantum dots may be less than a single nanometer in diameter. By way ofnon-limiting example, quantum dots may be formed of silicon, germanium,gallium, arsenide, indium phosphide, cadmium selenide, zinc sulfide,other substances, and/or a combination thereof.

The quantum dots may be synthesized using a variety of substances andprocesses. As one example, colloidally prepared quantum dots are freefloating and can be attached to a variety of molecules via metalcoordinating functional groups. By way of non-limiting example, thesegroups include thiol, amine, nitrile, phosphine, phosphine oxide,phosphonic acid, carboxylic acid, or other ligands. The ability toattach to other molecules greatly increases the flexibility of quantumdots with respect to the types of environments in which they can beapplied.

The shells may be deposited on the quantum dots. In some cases, theshells may be deposited using vapor deposition, direct deposition,and/or other deposition techniques to coat the quantum dots. By way ofnon-limiting example, the shells may include silicon, cadmium selenide(CdSe), cadmium sulfide (CdS), cadmium telluride (CdTe), and/or otherelemental or compound semiconductors. In an embodiment, the shells maybe doped with a metal, such as sodium (Na) or tin (Sn), or metal alloy.The shell material and the dopants may form covalent bonds. The shellsmay be implemented using any known or available methods or processes formanufacturing, producing, or generating the shells, so long as thecoating of the quantum dots by the shells do not adversely affect thequantum dots. In this regard, properties of the shells (e.g., materialproperties) and the deposition process for the shells are selected suchthat deposition of the shells does not dissolve or otherwise neutralizethe quantum dots. For example, the quantum dots may be neutralized whena reaction between the quantum dots and their shells cause the quantumdot to be unable to fluoresce.

In an embodiment, the quantum dots and shells of the nanostructures maybe implemented as any type of quantum dots and shells, respectively. Inthis regard, the quantum dots and shells may be manufactured using anyknown or available methods or processes for manufacturing, producing, orgenerating quantum dots and shells. In this example, the nanostructuresare incorporated into (e.g., mixed into, embedded in) a material. Inmany cases, the nanostructures are incorporated into the material priorto deposition, such that the deposition (e.g., by one or more printingnozzles) causes the material with the nanostructures distributed thereinto be deposited. The nanostructures are incorporated into the materialusing any known or available method for incorporating nanostructuresinto a material. Any technique known to a person of ordinary skill inthe art may be utilized.

In an embodiment, nanostructures of multiple sizes, shapes, and/ormaterials can be tethered or linked together to form molecules, attachedto a polymer backbone, linked or tethered to form chains, and/or linkedto form lattices. The nanostructures in these chains and lattices thatare of different size, shape, and/or material emit different wavelengthsignals in different patterns. The nanostructures of multiple sizes,shapes, and/or materials may be mixed together and deposited with thedeposition material and linked (e.g., by using various manufacturingoperations such as curing operations). In response to an excitationsignal, the linked nanostructures may provide a specific identifiablecode pattern, which may be multicolored (e.g., having multiplewavelength components) and can be identified by a unique nanostructurepattern, similar to a bar code. Thus, a nanostructure bar code withspecific fluoroscopic characteristics may be selectively or uniformlyembedded into the deposition material. In this regard, when the quantumdots are of multiple sizes, shapes, and/or materials and shells are ofmultiple sizes, shapes, and/or materials, the linked nanostructures mayprovide a specific identifiable code pattern when the shells are intactand another specific identifiable code pattern when the quantum dots areintact. In an embodiment, the code patterns may be utilized formonitoring of the manufacturing process, such as in determining whethermanufacturing characteristics have been satisfied.

FIG. 7 illustrates a flow diagram of an example process 700 for usingnanostructures to monitor a manufacturing process in accordance with anembodiment of the present disclosure. For explanatory purposes, theexample process 700 is described herein with reference to the system 100shown in FIG. 1; however, the example process 700 is not limited to thesystem 100 of FIG. 1. Note that one or more operations may be combined,omitted, and/or performed in a different order as desired.

At block 705, the computing device 105 determines parameters for amanufacturing process (e.g., an additive manufacturing process) and anassociated monitoring (e.g., evaluating) process. The determinedparameters may be provided to the additive manufacturing device 110,excitation device 115, and detection device 120. The parameters mayinclude material(s) for the nanostructures (e.g., quantum dots, shells,and dopants), amount of nanostructures to be incorporated into depositedmaterial(s), excitation signal wavelength or wavelength range, emittedsignal wavelength or wavelength range, number and dimensions of layersof deposited material, material(s) to be deposited in each layer,printer nozzle flow rate and/or temperature, manufacturing operationsand associated manufacturing characteristics, and/or other parametersassociated with the manufacturing process or the monitoring process. Insome cases, the determined parameters may be stored as the initialparameter values 230 in the memory 220 of the computing device 105.

At block 710, the additive manufacturing device 110 forms one or morelayers of an object, in which at least one of the layer(s) includesnanostructures distributed therein. Each nanostructure (e.g., 600) mayinclude a quantum dot (e.g., 605) and a shell (e.g., 610) encompassingthe quantum dot. The shell may be doped. The quantum dot and itsencompassing shell generally include different materials and exhibitdifferent properties, such as different melting points and band gaps. Inan embodiment, not all of the deposited layers are evaluated. In somecases, the deposited layers that are not evaluated do not havenanostructures distributed therein. In other cases, these depositedlayers may have nanostructures distributed therein. For example, inthese latter cases, the cost (e.g., time cost, component cost) and/orcomplexity associated with distributing nanostructures in the depositedmaterial of some layers and not in other layers may be higher thandistributing nanostructures in all deposited layers of material.

At block 715, the additive manufacturing device 110 performs amanufacturing operation on the layer(s). The manufacturing operation mayhave an associated manufacturing characteristic. In an embodiment, thequantum dots and the shells of the nanostructures may be configured suchthat the shells are removed (e.g., melted, dissipated) when themanufacturing operation is properly performed (e.g., while generallyleaving the quantum dots intact). The manufacturing operation may beconsidered to be properly performed when a manufacturing characteristichas been satisfied. In this regard, the shells being removed (while thequantum dots are intact) may be indicative of the manufacturingcharacteristic having been satisfied.

As an example, the manufacturing operation may include heating thelayer(s) of material at a specified temperature (e.g., for at least aminimum amount of time), in which the heating may cause the shells ofthe nanostructures to be removed (e.g., melted, dissipated). Themanufacturing characteristic is satisfied when the specified temperatureis reached. In this example, various parameters (e.g., material(s),size(s), shape(s)) of the shells and the quantum dots may be selectedsuch that, when the heating reaches the specified temperature, themelting point of the shell has been reached (e.g., to cause removal ofthe shells) whereas the melting point of the quantum dots has not beenreached (e.g., to leave the quantum dots intact).

As another example, the manufacturing operation may include applying apressure to the layer(s) of material (e.g., for at least a minimumamount of time). The manufacturing characteristic is satisfied when thepressure is reached. The shells may be configured to be removed and thequantum dots configured to remain mostly intact when the pressure hasbeen reached at the layer(s) of material. As another example, themanufacturing operation may be, may include, or may be a part of, acuring operation in which the layer(s) of material is maintained at aspecified temperature and a specified pressure. The shells may beconfigured to be removed and the quantum dots configured to remainmostly intact after the layer(s) of material is maintained at thespecified temperature and/or the specified pressure for at least aminimum amount of time.

At block 720, the excitation device 115 scans at least a portion of thelayer(s) using an excitation signal. For example, the excitation device115 may apply an excitation signal (e.g., EM radiation) having awavelength λ₁ to the portion of the layer(s). In some cases, theexcitation device 115 scans an entirety of the layer(s) (e.g., at leastone of the layers). The excitation device 115 may scan the entirety ofthe layer(s) using one or more excitation signals having wavelength λ₁.The excitation device 115 may include and/or may utilize multipleexcitation sources to scan multiple portions of the layer(s) at a time.In some cases, the excitation device 115 may move and/or rotate anexcitation source(s) to scan different portions of the layer(s).

At block 725, the detection device 120 detects an emitted signalprovided by at least a subset of the nanostructures distributed in theportion of the layer(s). The emitted signal may include EM radiationhaving a wavelength λ₂ from the shells of the nanostructures and/or EMradiation having a wavelength λ₃ from the quantum dots of thenanostructures (e.g., when the corresponding shells are at leastpartially removed). In an embodiment, the wavelengths λ₂ and λ₃ areselected to be sufficiently separated in wavelength such that thedetection device 120 can accurately determine how much of the emittedsignal can be attributed to emissions from the shells and how much fromthe quantum dots.

In some cases, blocks 715, 720, and 725 may be performed in parallel. Inthis regard, the emitted signal may be utilized as a gauge of whetherthe manufacturing operation is complete. For example, a curing operationcan be considered to be complete when the emitted signal from thenanostructures in the deposited material includes the λ₃ component fromthe quantum dots and negligible or no λ₂ component from the shells(e.g., the shells have been removed).

At block 730, the computing device 105 determines whether amanufacturing characteristic has been satisfied based on the emittedsignal. The manufacturing characteristic is associated with themanufacturing operation performed on the layer(s) of material at block715. The determination may be made after an amount of time (e.g., anamount of time specified in the initial parameter values) for themanufacturing operation has elapsed. The computing device 105 mayreceive information associated with the emitted signal from thedetection device 120 and/or derive the information based on informationreceived from the detection device 120. The information may identify thepresence (or lack of presence) of the λ₂ component (e.g., associatedwith the shells) and/or λ₃ component (e.g., associated with the quantumdots), intensities of these components, and/or locations of the layer(s)from which these signal components are received.

As indicated previously, the shells may be configured to be removedwhile the quantum dots remain intact when the manufacturingcharacteristic has been satisfied. As one example, the computing device105 may determine the manufacturing characteristic has been satisfiedbased on the presence of the λ₃ component in the emitted signal and lackof presence of the λ₂ component in the emitted signal. As anotherexample, the computing device 105 may determine the manufacturingcharacteristic has been satisfied when the emitted signal has a highintensity for the λ₃ component (e.g., associated with the quantum dots)and a low intensity (or no intensity) for the λ₂ component (e.g.,associated with the shells). In this example, a threshold(s) may be set(e.g., in the initial parameter values) for the intensity of the λ₂and/or λ₃ components. For instance, the computing device 105 maydetermine the manufacturing characteristic has been satisfied when theintensity of the λ₂ component is below a first threshold and when theintensity of the λ₃ component is above a second threshold.

When the manufacturing characteristic is determined to have beensatisfied, a determination is made as to whether a last layer of theobject has been completed at block 735. When the last layer of theobject has been completed, the additive manufacturing process ends atblock 740. When there are additional layer(s) of the object to bedeposited, the process 700 proceeds to block 710, such that theadditional layer(s) may be formed to obtain the completed object.

When the manufacturing characteristic is determined to not have beensatisfied, at block 745, the computing device 105 determines whether toproceed with the manufacturing process. The computing device 105 mayinterrupt the manufacturing process while making the determination. Insome cases, the computing device 105 may be provided autonomously (e.g.,set by user as part of the initial parameter values) to determinewhether to proceed with the manufacturing process. In other cases, thedetermination of whether to proceed with the manufacturing process maybe based on an explicit instruction from the user.

For example, the computing device 105 may provide for display themanufacturing characteristic that has not been satisfied and anyassociated information (e.g., wavelength components and associatedintensity levels at different locations of the layer(s)) to the user,and a prompt to the user regarding whether to proceed with themanufacturing process and/or how to adjust the manufacturing process. Insome cases, the computing device may provide for display to the userproposed adjustments to parameter values of the manufacturing process,and a prompt requesting the user to authorize, not authorize, and/ormanually set the parameter values. In these cases, the user canauthorize the proposed adjustments, end the manufacturing process (e.g.,discard the formed portions of the object), or manually set theparameter values.

The computing device 105 may provide any such information and/or promptsto the user via the display 210 of the computing device 105. In somecases, such as when the user is remote from the computing device 105,the computing device 105 may transmit (e.g., wirelessly transmit)messages to the user, such as an SMS text message and/or an email withan indication that the manufacturing characteristic has been determinedto not be satisfied, and a prompt requesting the user for authorizationto proceed with performing actions to adjust the additive manufacturingprocess.

In an embodiment, when the manufacturing characteristic is determined tonot have been satisfied, the computing device 105 may obtain (e.g.,determine) additional information associated with the manufacturingprocess and/or the object being manufactured by the manufacturingprocess. The additional information may be utilized to verify that themanufacturing characteristic has not been satisfied, determine theproposed adjustments to be provided to the user, and/or otherwise allowthe computing device 105 to autonomously determine whether to proceedwith the manufacturing process (e.g., with adjustments) or better informthe user. In this regard, since the manufacturing characteristic nothaving been satisfied may cause a defective final product, costsassociated with obtaining the information and determining whether toproceed with the manufacturing process (e.g., with or without adjustedparameter values) may be lower than ending the current manufacturingprocess, discarding the formed portions of the object, and starting witha new manufacturing process.

For example, the computing device 105 may transmit commands to thedetection device 120 to scan the deposited layer(s) to generate anintensity mapping. In some cases, the portion of the layer(s) may bescanned more extensively than the scan performed at block 720. Theintensity mapping may identify the wavelength components in the emittedsignal, their respective intensity levels, and/or other information atvarious locations of the formed layer(s). Based on the intensitymapping, the computing device 105 may determine areas and/or volumesassociated with poor diffusion or polymer coupling, which are generallyareas and/or volumes in which the intensity of λ₂ component is above athreshold and/or intensity of λ₃ component is below a threshold. Forexample, the manufacturing operation may be a curing operation thatcaused some portions to be cured properly while other portions wereinsufficiently cured.

Alternatively or in addition, the computing device 105 may transmitcommands to one or more imaging devices to capture image and/or videodata associated with the object formed in the manufacturing process. Thecaptured data may be processed to obtain the intensity mapping and/orsupplement the intensity mapping. For example, the captured visual datamay be processed to determine a smoothness/roughness of differentportions of the deposited layer(s), a thickness of the depositedlayer(s), a temperature associated with different portions of thedeposited layer(s), and/or other characteristics of the object. Thecomputing device 105 may generate proposed parameter adjustments basedon the captured visual data. In some cases, the detection device 120 mayinclude the imaging devices. In other cases, some or all of the imagingdevices may be separate from the computing device 105. The imagingdevices may be utilized to capture image and/or video data (e.g.,visible-light, infrared, and/or other wavelengths) throughout themanufacturing process. In other cases, the imaging device may beutilized primarily when the manufacturing characteristic is determinedto not have been satisfied, e.g. to conserve power and resources until apotential problem has been detected.

At block 750, the computing device 105 adjusts the additivemanufacturing process. In some cases, the adjustment(s) may be anadjustment(s) to an initial parameter value(s) and/or a previouslyadjusted parameter value(s). In some cases, the adjustment(s) mayinclude one or more manufacturing operations to fix specific areasand/or volumes of the layer(s) at which the manufacturing characteristicwas not satisfied. In this regard, the manufacturing operation(s) may belocalized to these specific areas and/or volumes. As indicatedpreviously, the adjustments may be autonomously proposed by thecomputing device 105 (e.g., at block 745) and authorized by the userand/or provided by the user to the computing device 105.

In some cases, any adjustments made and/or proposed by the computingdevice 105 may be stored in the adjusted parameter values 235 in thememory 220 of the computing device 105. The information may alsoindicate the proposed adjusted parameter values, whether or not the userauthorized the proposed values, and/or information utilized to obtainthe proposed adjusted parameter values (e.g., intensity maps, othercaptured image/video data), such as to facilitate the generation and/oradjustment of parameter values for future manufacturing processes.

Thus, using various embodiments, the nanostructures may be utilized tomonitor the manufacturing process (e.g., in real time and/or as part ofa post-manufacturing inspection). The wavelength components included ina signal emitted from the layer(s) of material with the nanostructuresdistributed therein can be utilized to determine whether manufacturingoperations are properly performed and address potential flaws whendetected.

In an embodiment, the emission from the quantum dots may be indicativeof whether the quantum dots were distributed properly. For example, ifthe quantum dots are configured to be removed (e.g., dissolved, melted)as part of the manufacturing operation, the monitoring process may beunable to differentiate between whether the quantum dots were removed bythe manufacturing operation or the quantum dots were not mixed inproperly with the deposition material. Thus, in various embodiments,detection of signal from the quantum dots is utilized as an indicationthat the manufacturing operation is properly performed. In this regard,the quantum dots are utilized as a positive indicator that is present(rather than removed) to signify that a manufacturing operation isproperly performed.

Although the foregoing description is with reference to a two levelsystem involving a quantum dot and a shell, in some aspects, more thantwo levels may be utilized. For example, the quantum dot may beencompassed by multiple outer shells. Different shells may be configuredwith different properties and detected manufacturing characteristics.For example, an outer shell may be utilized for detecting a pressureapplied to a layer of material, an inner shell may be utilized fordetecting a temperature applied to the layer of material, and so forthfor additional shells. In this example, the forming of the layer ofmaterial may be defined such that a pressure applied to the layer ofmaterial causes the outer shell to be removed, and then heat applied tothe layer of material causes the inner shell to be removed, and so forthin cases where there are additional shells. In some cases, thenanostructures and manufacturing process may be designed such that,after the manufacturing operations have been performed properly, theonly part of the nanostructures remaining may be the quantum dots.

Where applicable, the various hardware components and/or softwarecomponents set forth herein can be separated into sub-componentscomprising software, hardware, or both without departing from the spiritof the present disclosure. In addition, where applicable, it iscontemplated that software components can be implemented as hardwarecomponents, and vice-versa.

Software in accordance with the present disclosure, such as program codeand/or data, can be stored on one or more non-transitory machinereadable mediums. It is also contemplated that software identifiedherein can be implemented using one or more general purpose or specificpurpose computers and/or computer systems, networked and/or otherwise.Where applicable, the ordering of various steps described herein can bechanged, combined into composite steps, and/or separated into sub-stepsto provide features described herein.

Embodiments described above illustrate but do not limit the invention.It should also be understood that numerous modifications and variationsare possible in accordance with the principles of the present invention.Accordingly, the scope of the invention is defined only by the followingclaims and their equivalents.

The invention claimed is:
 1. A method comprising: forming a layer ofmaterial comprising a plurality of nanostructures distributed therein,wherein each nanostructure comprises a quantum dot and a shellencompassing the quantum dot, wherein the shells are configured to emita first wavelength in response to an excitation signal, wherein thequantum dots are configured to emit a second wavelength in response tothe excitation signal, and wherein the layer of material is part of anobject formed based on an additive manufacturing process; performing amanufacturing operation on the layer of material, wherein themanufacturing operation comprises heating the layer of material;applying the excitation signal to at least a portion of the layer ofmaterial; detecting an emitted signal from the portion of the layer ofmaterial, wherein the emitted signal is provided by at least a subset ofthe plurality of nanostructures in response to the excitation signal,and wherein the emitted signal has a first intensity at the firstwavelength and a second intensity at the second wavelength; determiningwhether a temperature has been reached for the layer based at least onthe first intensity at the first wavelength and the second intensity atthe second wavelength, wherein the temperature is between a meltingpoint associated with the shells and a melting point associated with thequantum dots; and interrupting the additive manufacturing process if thetemperature is determined to not have been reached.
 2. The method ofclaim 1, wherein the shells comprise at least one semiconductor materialdoped with at least one metal material, and wherein the first and secondwavelengths are associated with lower energy than the excitation signal.3. The method of claim 1, wherein: the first wavelength is based on afirst band gap associated with the shells of the nanostructures in theportion; the second wavelength is based on a second band gap associatedwith the quantum dots of the nanostructures in the portion; and thedetermining is based at least on whether the first intensity is below afirst threshold and whether the second intensity is above a secondthreshold.
 4. The method of claim 1, wherein: the manufacturingoperation is performed prior to the applying, the manufacturingoperation causes at least one shell of the nanostructures in the portionto be removed, and the removal of the at least one shell causes awavelength of the emitted signal to comprise the second wavelength. 5.The method of claim 4, wherein the at least one shell is removed whenthe heating causes the layer of material to reach the temperature. 6.The method of claim 4, wherein the manufacturing operation furthercomprises applying a pressure to the layer of material, the methodfurther comprising: determining whether the pressure has been reachedfor the layer based at least on the first intensity and the secondintensity; and interrupting the additive manufacturing process if thepressure is determined to not have been reached, wherein the at leastone shell is removed when the pressure has been reached for the layer ofmaterial.
 7. The method of claim 6, wherein the manufacturing operationcomprises a curing operation in which the layer of material ismaintained at the temperature and the pressure, and wherein the at leastone shell is removed after the layer of material is maintained at thetemperature and the pressure for at least a minimum amount of time. 8.The method of claim 1, wherein the layer of material comprises a firstlayer, the method further comprising: forming a second layer of thematerial over the first layer, wherein the forming is performed whilethe determining is performed; and repeating the applying, the detecting,and the determining for the second layer.
 9. The method of claim 1,wherein the layer of material comprises a first layer, the methodfurther comprising: forming a second layer of the material comprising asecond plurality of nanostructures distributed therein; applying theexcitation signal to at least a portion of the second layer; anddetermining whether a temperature condition has been satisfied for thesecond layer based at least on whether a second emitted signal from theportion of the second layer is detected.
 10. The method of claim 9,further comprising: performing a manufacturing operation on the secondlayer; and forming a third layer of the material, wherein the formingthe third layer is performed while the determining for the first layeris performed and the manufacturing operation is performed on the secondlayer.
 11. The method of claim 9, wherein the temperature condition isdetermined to not have been satisfied for the second layer when noemitted signal is detected.